Answer:
The excerpt that represents the author's opinion on the subject is:
B. I happen to think that animals from shelters appreciate good homes even more than pet shop animals do, making them more faithful and affectionate.
Step-by-step explanation:
The other options are stating facts. The first one explains that animals are sent to foster homes when the shelter gets too full. The third one states that animals are well taken care of. And the last one says pets only leave the shelter when properly vaccinated. Only the second option presents an opinion instead of a fact. Here, the author talks about what he thinks and feels. In the author's opinion, animals from shelters are grateful and affectionate, even more than animals from pet shops. Some people may disagree with this statement, after all it is just an opinion, not a proved fact.